(19)
(11) EP 0 284 438 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
31.10.1990 Bulletin 1990/44

(43) Date of publication A2:
28.09.1988 Bulletin 1988/39

(21) Application number: 88302733.6

(22) Date of filing: 28.03.1988
(51) International Patent Classification (IPC)4: H01L 39/12, H01L 39/24
(84) Designated Contracting States:
DE FR GB

(30) Priority: 27.03.1987 JP 75201/87

(71) Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
Atsugi-shi Kanagawa-ken, 243 (JP)

(72) Inventor:
  • Yamazaki, Shunpei
    Setagaya-ku Tokyo 157 (JP)

(74) Representative: Milhench, Howard Leslie et al
R.G.C. Jenkins & Co. 26 Caxton Street
London SW1H 0RJ
London SW1H 0RJ (GB)


(56) References cited: : 
   
       


    (54) Superconducting materials and methods of manufacturing the same


    (57) A high Tc superconducting ceramic material of the general formula (A1-xBx)yCuzOw where A represents a rare earth element and B represents one or more alkaline earth metals for example is manufactured by a process designed to limit significantly the presence of alkali metal impurities such as lithium, sodium and potassium in the final material. Very high purity raw materials are utilized and are washed in very high purity water in order to wash out any soluble alkali metal impurities. Carbon and nitrogen impurities are also minimized as too are halogen impurities. Superconducting materials having a Tc and Tco in excess of 100°K are obtained.







    Search report